1. Field of the Invention
The present invention relates generally to agricultural airplane guidance systems, and more particularly, to laser guidance devices that assist pilots in navigation by displaying present flight data by means of a reflective propeller and laser beam that indicate to a pilot which flight direction to direct their aircraft in order to follow a desired flight path.
2. Description of Related Art
Devices that display information to assist a pilot to maintain a flight path are common and are known in the patent literature. There are many devices and methods to display present flight information to a pilot regarding flight characteristics of an aircraft. However, some flight plans have performance or safety characteristics that are adversely affected when a pilot must redirect his or her line of sight to view a display. Therefore, displays that reduce the distance over which a pilot must redirect his or her line of sight during flight are desired.
For example, when spraying crops with an airplane, the altitude of the aircraft is very low and the flight course is even more exacting. To fly a flight course as precisely as possible requires momentary and often instantaneous feedback regarding the flight direction of the aircraft, therefore requiring that the pilot be able to quickly and easily view the flight data to insure flight safety.
The patent literature provides various and different feedback displays. U.S. Pat. No. 5,181,028 issued to Tom Sharpe et al. on Jan. 19, 1993 discloses a display device in the form of eye glasses that are worn by a pilot. A three dimensional display provides roll, pitch and heading indicators within a spherical grid on a cathode ray tube (CRT) screen. As discussed, the requirement that a pilot redirect his sight to read a display is not efficient in some flight plans thus making this type of apparatus undesirable.
U.S. Pat. No. 4,860,007 issued to Michael Konicke et al. on Aug. 22, 1989 teaches an integrated flight display generated on a CRT. Again, redirecting the sight of a pilot to view the CRT during flight limits the usefulness of the display and hinders safety under certain flight situations.
U.S. Pat. No. 5,614,897 issued to Simon Durnford on Mar. 25, 1997 describes an instrument display panel that indicates aircraft speed and heading. The pilot must redirect his or her line of sight to read the display panel. Placement of the display panel near the line of sight of the pilot reduces the distance over which a pilot must redirect his or her line of sight. However, a display panel would have to be attached to the aircraft and a pilot would have to redirect his line of sight to at least the nose of the aircraft to see the display panel. Flight displays that require a pilot to redirect his or her line of sight during flight hinder the ability of the pilot to navigate and fly safely.
To date, inventions display flight information using CRTs or liquid display technology that are attached within the aircraft cockpit or on the nose of the aircraft. Present aircraft displays suffer from the limitation that a pilot is required to redirect their line of sight away from flying the aircraft, at least momentarily, and toward a display unit located on the aircraft to interpret the information displayed.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.